1. Field of the Invention
The present invention relates to an image correction circuit having a function of performing a correction process on an image signal, an image correction method and an image display.
2. Description of the Related Art
Apparatuses such as television receivers, VCRs (Video Caccette Recorders), digital cameras, television cameras or printers typically have an image processing function which makes image quality correction to an input image, and then outputs the input image (for example, functions such as luminance or contrast control, and contour correction). Such a function is effectively applied mainly to a totally dark and low-contrast image or a blurred image.
Among these functions, in general, the contrast control is performed by correcting a gamma curve which represents so-called gamma characteristics, and as an example, there is a method of using a luminance distribution as the histogram distribution of an input image. More specifically, for example, as shown in FIG. 14A, in the case where a luminance distribution (a luminance distribution 106A) is distributed in a low luminance region (a black level region), for example, as shown in FIG. 14B, a gamma curve is corrected from L101 to L102. Likewise, for example, as shown in FIG. 15A, in the case where a luminance distribution (a luminance distribution 106B) is distributed in a high luminance region (a white level region), for example, as shown in FIG. 15B, a gamma curve is corrected from L101 to L103, and, for example, as shown in FIG. 16A, in the case where a luminance distribution (a luminance distribution 106C) is distributed in an intermediate luminance region, for example, as shown in FIG. 16B, a gamma curve is corrected from L101 to L104. In addition, the amount of correction which is set at each luminance level at the time of correcting the gamma curve is called gain.
Moreover, for example, in Japanese Unexamined Patent Application Publication Nos. 2006-93753 and 2005-175933, there are disclosed contrast improvement methods in which the luminance distribution of an input image is detected as a histogram distribution, and a gamma curve is corrected at each distribution peak on the basis of the luminance histogram distribution.